T-Mobile likes to tout the speed of its 4G LTE network, often saying that it’s the fastest in the U.S. Recently, though, that claim was met with some skepticism.

The National Advertising Division, which is overseen by the Council of Better Business Bureaus, has recommended that T-Mobile stop claiming that it has the fastest 4G LTE network. This is following a complaint from Verizon, which argued that the results T-Mo was basing its claim on were from Speedtest results that may have been purposely slowed by Verizon for customers that used a heavy amount of data in a single month.

Here’s the NAD’s statement on the matter:

“Following its review, NAD concluded that the Ookla and Open Signal Speed test results in the month after Verizon introduced unlimited data plans might have had a bias in favor of T-Mobile and as a result did not support a comparative claim that T-Mobile has the fastest 4G LTE network. NAD recommended T-Mobile discontinue claims that it has the fastest 4G LTE network.”

Following the decision, Verizon said:

“In our opinion, their claims have been based on cherry-picked data and have misrepresented facts.”

T-Mobile initially agreed to follow the NAD’s recommendation, but today T-Mo said that it wouldn’t stop saying that it’s got the fastest 4G LTE network because it’s got newer testing data that backs up its claims:

“NAD previously recognized third-party crowd-sourced data as a way to look at network performance, so we looked at the latest results, and verified what we already knew! T-Mobile is still the fastest LTE network and we’ll continue to let consumers know that!”

Talking up the speed of its 4G LTE network is one of T-Mobile’s main marketing points, so it’s no surprise that T-Mo is going to keep hammering on that, especially if it’s got data that supports it.

Source: Fortune